WATER MCQs 10 min Score: 0 Attempted: 0/10 Subscribe 1. Rain water contain: (A) Salts (B) Suspended impurities (C) Gases (D) Biological impurities 2. Underground water contains: (A) Gases (B) Salts (C) Suspended impurities (D) Biological impurities 3. Water which gives lather when treated with soap is known as: (A) Soft water (B) Hard water (C) Mineral water (D) De-mineral water 4. By boiling water ______ hardness of water can be removed: (A) Permanent (B) Temporary (C) Both a and b (D) None of these 5. In zeolite method calcium and magnesium ions of hard water are replaced by: (A) Zinc (B) Iron (C) Chromium (D) Sodium 6. Compound which causes temporary hardness of water is: (A) Ca(HCO₃)₂ (B) CaCl₂ (C) CaSO₄ (D) CaCO₃ 7. Compound that causes temporary hardness of water is: (A) Mg(HCO₃)₂ (B) MgCl₂ (C) MgSO₄ (D) MgCO₃ 8. Boiling can remove ______ hardness of water: (A) Permanent (B) None of these (C) Both a and b (D) Temporary 9. Percentage of NaCl in sea water is: (A) 5% (B) 3.5% (C) 2.5% (D) 4% 10. Which one of the following compound causes temporary hardness of water? (A) NaCl (B) MgCl₂ (C) Ca(HCO₃)₂ (D) CaCl₂
